Automating remote switches when you're cheap

Wemos are switches you can operate from wifi and remotely.

wemo

Wemos nice and all. But they have two downsides:

    1. They are expensive.
    1. I don't trust them.

Here's some of why:

google results for "wemo security flaw"

I like the Lan of Things, not the Internet of Things. So here's what i did:

I bought cheap (but not too cheap) wireless switches. 3 for NZ$37 at bunnings.

I tried a few libraries for arduino that work with other switches. I was able to decode the signal from the remote, but it changes every press. I'm not sure what's going on. I couldn't use simple replay. So, in frustration i opened the remote up.

remote

and unsoldered the switches, added wires instead.

remote

I then powered it from the Arduino uno's 3.3V output - and, using some voltage dividers, hooks each switch up to the GPIO of the uno.

inside the remote

Now, when i set a pin low, it grounds the switch - this causes the remote to transmit the code to tell a switch to turn off or on.

And it works.

Light switch remote, wired into arduino uno from Brenda Wallace on Vimeo.

I hooked this up with Mysensors.org, and into Openhab. All the goodness, for about $15 a switch.